The most recent Pest Management Strategic Plan updates a 2004 document that was less national in scope, according to a news release.
One area that's improved over the nine years is managing thrips and the iris yellow spot virus they carry.
Cultivar selection factors into reducing thrips problems, according to Mark Uchanski, an assistant horticulture professor at New Mexico State University, Las Cruces, and a plan contributor.
“More glossy and green foliage is less attractive to thrips," he said in the release. "More waxy and blue foliage is more attractive.”
Plant breeders also are developing more vigorous onion cultivars.
“They’re better able to stand up to the feeding of thrips,” Howard Schwartz, a Colorado State University plant pathology professor and lead author of the plan, said in the release. “That’s one thing we’re able to share through field trials.”
Other practices that have helped include crop rotation, better management of debris and weeds where thrips populations can grow, and scouting to better time pesticide applications.
Nevertheless, thrips still remain the leading U.S. onion pest, especially when combined with iris yellow spot virus.